Suitable synthetic peptides, attached to appropriate carriers, lead to antibodies capable of cross-reacting with proteins containing the peptides in their sequences. This has been shown to be true for hen egg-white lysozyme, for the coat protein of the bacteriophage MS2, and for influenza hemagglutin. Similar results have been reported on protein M of Streptococcus pyogenes, diphtheria toxin hepatitis virus, and foot and mouth disease virus. In several cases of viruses and toxins, the antibodies formed were capable of neutralizing the biological activities.
The purpose of the present invention is to provide synthetic peptides capable of provoking antibodies neutralizing efficiently cholera toxin and other similar toxins, such as heat-labile toxin of E. Coli.
The toxin of Vibrio cholerae is composed of two subunits, A and B.
Subunit A activates adenylate cyclase which triggers the biological activity, whereas subunit B is responsible for binding to cell receptors, and expresses most immunopotent determinants. Antibodies to the B subunit are capable of neutralizing the biological activity of the intact toxin. The B subunit (choleragenoid) is a pentamer, each of the chains containing 103 amino acid residues.
The invention relates to the synthesis of several peptides derived from the B subunit of the cholera toxin, and to antibodies neutralizing the intact cholera toxin as well as other toxins, such as heat-labile toxin of E. Coli.